A device for controlling pressure in riser-inflated dual-gradient drilling

Abstract

The invention discloses a pressure control device for double-gradient drilling with riser inflation, which consists of an upper riser, an upper gas injection channel, a balance communication device, a lower gas injection channel, a drill pipe, a lower riser, a blowout preventer, and a seabed high-pressure pump , a voltage stabilizer, an emergency shut-off solenoid valve C, a locking device, a high-pressure hydraulic oil delivery pipe and a drilling platform. The upper riser extends downward from the drilling platform, and the lower riser extends downward from the locking device. There is a high-pressure hydraulic oil delivery pipe; the upper port of the balance communication device is connected to the upper riser above the locking device, and the lower port is connected to the lower riser below the locking device; the blowout preventer is arranged at the wellhead of the seabed; the seabed high-pressure pump The pipeline has an emergency cut-off solenoid valve C, and the subsea high-pressure pump has a pressure-reducing pipeline and a boosting pipeline. The device can timely and accurately control the bottom hole pressure, adapt to changing actual engineering conditions, and ensure the safety of deep sea drilling.

Description

technical field [0001] The patent of the present invention relates to a device for controlling pressure in riser-inflated dual-gradient drilling in the process of ocean deepwater drilling. Background technique [0002] With the increase of our country's exploration and development of offshore oil and natural gas, there are more and more drilling problems in various complex areas. The application of conventional drilling technology in these areas may lead to many drilling problems: a large amount of drilling fluid loss caused by pressure leakage formation, Blowout accidents, pipe sticking and other downhole complex accidents; at the same time, they will also cause damage to the production layer. Especially in the process of drilling, a large amount of drilling fluid is often leaked, or even leaked and lost, causing blowout accidents, causing huge property losses and personal injuries. In addition, when drilling wells in many areas of our country, the safety problems during n...

AI Technical Summary

Problems solved by technology

[0002] With the increase of our country's exploration and development of offshore oil and natural gas, there are more and more drilling problems in various complex areas. The application of conventional drilling technology in these areas may lead to many drilling problems: a large amount of drilling fluid loss caused by pressure leakage formation, Blowout accidents, pipe sticking and other downhole complex accidents; at the same time, it will also cause damage to the production zone

Compared with long-distance well sections, the amount of air charged cannot quickly and effectively change the bottomhole pressure in a short period of time, let alone make timely and effective responses to the ever-changing actual engineering conditions

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